Modern automotive engines typically utilize a catalytic converter to reduce the exhaust gas emissions produced by the engine. Such converters operate to chemically alter the exhaust gas composition produced by the engine to help meet various environmental regulations governing tailpipe emissions. Catalytic converters typically operate at peak efficiency when the temperature of the catalytic material within the converter is within a certain specified temperature range. Continued operation of the converter at a temperature greater than the specified temperature range, however, leads to degradation of the catalyst material within the converter. Such degradation leads to reduced converter operating life and to increased tailpipe emissions.
Accordingly, there exists a need to accurately determine the operating temperature of a catalytic converter and to limit the temperature of the converter during vehicle operation.